How to find objectId as an foreign key in mongo - mongodb

Question

How can I find the value of ObjectId in whole database for any field in mongo ,
it might be use in some collections for various fields as a reference?
"fourk_runs": [{
"Objectid": "6299b9f00f09ff045cc15d"
}],
"fourk_pass_fail": [{
"Objectid": "6299b9f00f09ff045cc152"
}],
"dr_runs": [{
"Objectid": "6299b9f00f09ff045cc154"
}],
I try this command , but it does not work
db.test.find( { $text: { $search: "4c8a331bda76c559ef04" } } )

Answer 1

In MongoDB, the references are mostly used for the normalization process. The references from the children's table (usually an ObjectID) are then embedded in the parent table. When reading the information, the user has to perform several queries in order to retrieve data from multiple collections.
For example, we will take the next two collections, parts and products. A product will contain many parts that will be referenced in the product collection.
parts Collection:
db.parts.findOne()
{
_id : ObjectID('1111'),
partno : '7624-faef-2615',
name : 'bearing',
price: 20,000
}
products Collection:
db.products.findOne()
{
name : 'wheel',
manufacturer : 'BMW',
catalog_number: 1134,
parts : [ // array of references to Part documents
ObjectID('1111'), // reference to the bearing above
ObjectID('3f3g'), // reference to a different Part
ObjectID('234r'),
// etc
]
}
To receive the parts for a particular product, we will first have to fetch the product document identified by the catalog number:
db.products.findOne({catalog_number: 1134});
Then, fetch all the parts that are linked to this product:
db.parts.find({_id: { $in : product.parts } } ).toArray();